Hymenoxys ambigens is a species of flowering plant in the daisy family known by the common name Pinaleño Mountains rubberweed. It is native to the states of Arizona and New Mexico in the southwestern United States. Hymenoxys ambigens is a perennial herb up to 150 cm (5 feet) tall. Leaves have very narrow lobes resembling branching threads. One plant can produce an array of 25–400 small yellow flower heads, each head with 3-5 ray flowers and 6–15 disc flowers.